move xlib and gtk plugins into the main tree from graphviz-cairo

diff --git a/plugin/gtk/interface.h b/plugin/gtk/interface.h
new file mode 100644 (file)
index 0000000..75b41be
--- /dev/null
+++ b/plugin/gtk/interface.h
@@ -0,0 +1,5 @@
+/*
+ * DO NOT EDIT THIS FILE - it is generated by Glade.
+ */
+
+GtkWidget* create_window1 (void);